Spark plug



J( E' HUDSON Aug. 26, 1952 SPARK PLUG Fi1ed jan. 24 1949 nal, and electrica1 insulation in Said passageway between said center electrode and said body, said electrica1 insu1ation continuing beyond said tubular extension to coat Said extension and the outer surface f said body 7- A Spark plug having a meta11ic she11 including a pair of spced substantia11y c0-planar terrlinating annular skirts extending in one direc tion therefron1 and a tubular continuation ex tending in the 0pp0site direction therefrom, an axial passageway through said shell and extension, a center electrode axially extending through said passageway tern1inating at one end to pro vide a spark gap between said center electrode nd the inner one of said skirts and terninating a't its opp0site end beyond said extension to pr0 vide a tern1ina1, and electric insu1ation thern10 set in said passageway between said center elec trode and Said She11, Said insulation providing a plastic sea1between said center electrode and said shell and continuing therefron1 to provide a coat ing for said tubular continuation' 6 BEFEEENCES OITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number NaIne Date 853,425 Sander 1"ay 1 1907 913,453 Bateholts Feb 23, 1909 2 168 206 aStings Aug 1) 1939 2 269,076 Bo11 Jan 6, 1942 2,300,66 Buening 1Tov. 3 192 2 355 163 JackSon Aug 8, 194

2 357,60-2 Peters et a*1 Sept' 5 194:4

2,359,21 Higgins Oct 3 19 FOREIGN PATENTS Nufnber country Date 54,723 1Tetherlands June 15, 1943 

